In communications systems, base stations are provided that transmit signals to and receive signals from mobile terminals. Conventionally, a base station with an RF transceiver is collocated with a mast that has one or more antennas.
However, in the Remote Radio Head concept, a centrally located base station control unit (Node B in a W-CDMA communication system) is provided that is located some distance from the mast and antennas. In this case, an RF transceiver is provided at each mast, separate to the base station control unit.
This concept means that a single base station control unit can generate the transmission signals for a large number of users and map the signals onto the appropriate RF transceivers and antennas.
Typically, a separate implementation would be used for each antenna; there would be no sharing of processing resources between the streams and there would be a maximum number of users that could be allocated to each stream. For example, if there were sixty-four antennas, there would be sixty-four separate processing streams. These processing streams will consume a significant amount of hardware resources, even though they are likely to only be lightly loaded most of the time (i.e. the number of users supported will be much less than the maximum number of users per antenna).
Therefore, it is an object of the invention to provide a processor for a base station control unit that overcomes, or at least significantly mitigates, the disadvantages associated with the implementation described above.